Apparatus for controlling an odometer and speedometer system of a vehicle

Abstract

Apparatus for controlling an odometer and speedometer system of a vehicle, adjustable for vehicle parameter variations, such as tire size and axle ratio, including a transducer for generating a plurality of initial pulses in response to vehicle movement which pulses control both the vehicle odometer and speedometer. The initial pulses are multiplied by a multiplying factor to produce a train of pulses for each initial pulse. The multiplying factor is in binary form and is selected either according to the position of an array of switches or according to a number retained in a programmable downcounter. The train of pulses is divided by a fixed number to create a driving signal for the odometer and is converted by a frequency converter to drive the speedometer.

I claim: 
     
       1. Apparatus for controlling an odometer and speedometer of a vehicle cooperating with a rotatable element of said vehicle indicative of movement of said vehicle, comprising: transducer means for generating initial pulses in response to rotation of said rotatable element;   multiplying means connected to said transducer means for producing a train of pulses upon receipt of each initial pulse, said multiplying means including means for selecting a multiplying factor corresponding to an existing condition of the vehicle affecting the distance covered by the vehicle per revolution of said element;   divider means receiving the train of pulses for dividing the train of pulses by a fixed number to produce a subsequent pulse train having a frequency suitable for driving said odometer;   means for connecting said odometer to receive said subsequent pulse train;   frequency conversion means for converting said train of pulses into a signal suitable for driving the speedometer; and   means for connecting said speedometer to said frequency conversion means.   
     
     
       2. The apparatus according to claim 1 wherein said means for selecting a multiplying factor comprises an array of switches which are programmable to generate the multiplying factor in binary form. 
     
     
       3. The apparatus according to claim 2 wherein the selection means includes a plurality of separate switch arrays wherein each array of switches is programmable to generate separate multiplying factors in binary form and wherein each input is associated with a separate rear axle ratio of the vehicle. 
     
     
       4. The apparatus according to claim 1 wherein said multiplying means includes: an oscillator for generating the train of pulses;   a counter for limiting the number of pulses in each train of pulses to a number equal to said multiplying factor, wherein said counter communicates with said selecting means; and   flip-flop means communicating with said transducer means and with said oscillator for initiating operation of said oscillator upon receiving an initial pulse, said flip-flop means cooperating with said selecting means and said counter for resetting said counter after said counter has counted to said multiplying factor and for turning off said oscillator when said counter is reset.   
     
     
       5. The apparatus according to claim 4 wherein said means for selecting a multiplying factor includes an array of switches which are programmable to generate the multiplying factor in binary form. 
     
     
       6. The apparatus according to claim 5 wherein said selection means includes a plurality of separate switch arrays wherein each array of switches is programmable to generate separate multiplying factors in binary form and wherein each switch array corresponds to a separate rear axle ratio of the vehicle. 
     
     
       7. The apparatus according to claim 1 wherein said frequency conversion means comprises frequency-to-voltage conversion means and said speedometer comprises a meter responsive to current produced by said voltage. 
     
     
       8. Apparatus for controlling an odometer and speedometer of a vehicle cooperating with a rotatable element of said vehicle indicative of movement of said vehicle, comprising: transducer means for generating initial pulses in response to rotation of said rotatable element;   multiplying means for producing a train of pulses upon receipt of each initial pulse, said multiplying means including means for selecting a multiplying factor corresponding to an existing condition of the vehicle affecting the distance covered by the vehicle per rotation of said element;   said selecting means including means, responsive to the number of rotations of said rotatable element caused when said vehicle is driven over a measured distance, for programming said multiplying means by providing said selecting means with signals representing a number equivalent to said multiplying factor;   divider means receiving said train of pulses and dividing said train of pulses by a fixed number to produce a subsequent pulse train having a frequency suitable for driving said odometer;   means for connecting said odometer to receive said subsequent pulse train;   frequency conversion means for converting said train of pulses into a signal suitable for driving said speedometer; and   means for connecting said speedometer to said frequency conversion means.   
     
     
       9. The apparatus according to claim 8 wherein said multiplying means includes: an oscillator for generating said train of pulses;   a counter for limiting the number of pulses in each train of pulses to the multiplying factor, wherein said counter is responsive to said selecting means which determines said multiplying factor; and   flip-flop means, responsive to said transducer means, for initiating operation of said oscillator upon receiving an initial pulse and communicating with said selecting means and counter for resetting said counter after said counter has counted to said multiplying factor and for turning off the oscillator when said counter is reset.   
     
     
       10. The apparatus according to claim 9 wherein said counter and selecting means are programmable in binary form. 
     
     
       11. The apparatus according to clain 10 wherein said selecting means includes a second counter responsive to said transducer means; a comparator responsive to said second counter and communicating with said first named counter and flip-flop;   said second counter adapted to signal said flip-flop to reset said first-named counter and to turn off said oscillator.   
     
     
       12. The apparatus according to claim 11 wherein said second counter includes: means for presetting said counter with a number from which to count down;   switch means for initiating operation of said second counter when said vehicle commences moving over said measured distance, and for stopping operation of said second counter upon covering said measured distance; and   divider means for dividing the initial pulses by a fixed number to reduce the number of pulses applied to said second counter.   
     
     
       13. The apparatus according to claim 8 wherein said frequency conversion means comprises frequency-to-voltage conversion means and said speedometer comprises a meter responsive to current produced by said voltage. 
     
     
       14. The apparatus according to claim 8 wherein said selecting means comprises means for automatically establishing said multiplying factor to provide a substantially constant number of pulses to said odometer for a range of the number of revolutions of said rotating element per measured distance traveled by said vehicle. 
     
     
       15. The apparatus according to claim 14 wherein said range is between about 800 and 1200 revolutions per mile.